This lesson has been written for GCSE students, with the main focus being to introduce reversible reactions, show them how to represent them in both word and symbol equations, and to look at some well-known examples. Related topics such as the position of the equilibrium and endothermic and exothermic reactions are briefly mentioned so that students can recognise the potential crossover between topics. Some time is taken during the lesson to challenge the students to write a balanced symbol equation having been given a description of a reversible reaction. This task is differentiated with an assistance sheet so that all are able to access the learning. There are a number of these progress checks in this short lesson so that students can assess their understanding on a regular basis. Students will learn that the reaction in one direction will be exothermic and why this matters in terms of temperature and the equilibrium position. Increasing pressure and the number of moles is also discussed and an answer explained.

This is a fast-paced lesson which goes through the main steps of selective breeding and looks at the potential risks of this process. The lesson begins by looking at the characteristics of a number of organisms that would be selected. Time is taken to ensure that students understand that selective breeding is not a new thing and has been going on for a very long time and therefore some of the problems associated with this are now being experienced. The actual process is reduced down into 5 steps which can be recalled and applied to questions. The remainder of the lesson looks at the potential issues with selective breeding. The reduction in the nose size of pugs is explored as an example of the health problems which bred animals may face. This lesson has been written for GCSE students.

A fully-resourced lesson that looks at the different sampling methods that can be used to estimate the populations of animals and plants in a habitat and to analyse how their distribution is affected, The lesson includes a detailed and engaging lesson presentation (56 slides) and differentiated worksheets so that students of different abilities are challenged and can access the work. The lesson begins by looking at the use of a quadrat to estimate the population of plants in a habitat. There is a focus on the mathematical calculations associated with the method and students are given hints and worked examples so that any common misconceptions are addressed. Moving forwards, students are introduced to the capture-mark-recapture technique to sample animals. The rest of the lesson looks at alternative pieces of apparatus, such as the sweep net, and discusses situations when these would be used. This lesson has been written for GCSE students (14 - 16 year olds in the UK) but is appropriate for both younger students who are learning about ecology and also for A-level students who need a recap on this topic.

This lesson guides students through the use of the chi-squared test to determine the significance of the difference between observed and expected results. It is fully-resourced with a detailed PowerPoint and differentiated worksheets that have been designed to cover point 6.1.2 © of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of the test to compare the observed and expected results of a genetic cross The lesson has been written to include a step-by-step guide that demonstrates how to carry out the test in small sections. At each step, time is taken to explain any parts which could cause confusion and helpful hints are provided to increase the likelihood of success in exam questions on this topic. Students will understand how to use the phenotypic ratio to calculate the expected numbers and then how to find the critical value in order to compare it against the chi-squared value. A worked example is used to show the working which will be required to access the marks and then the main task challenges the students to apply their knowledge to a series of questions of increasing difficulty.

An engaging and informative lesson presentation (43 slides) that shows students how to write accurate chemical formulae for ionic compounds. In order to write accurate chemical formulae, students need to know the charges of the ions involved. For this reason, the lesson begins by reminding students how they can use the Periodic Table to work out the charge of the charged atoms. Students are shown how they can use these ion charges to write the formula and then are given the opportunity to apply this to a number of examples. Moving forwards, students are shown how some formulae need to contain brackets. The lesson finishes with a competition called “Ye Olde Chemical Formula Shop” where students get points if they are the first to work out the formula of a given substance. This lesson has been written for GCSE students.

This engaging and fully-resourced lesson looks at how genetic drift can arise after a genetic bottleneck or as a result of the Founder effect. The detailed PowerPoint and accompanying resources have been designed to cover the fourth part of point 7.3 of the AQA A-level Biology specification which states that students should be able to explain the importance of genetic drift in causing changes in allele frequency in small populations A wide range of examples are used to show the students how a population that descends from a small number of parents will have a reduction in genetic variation and a change in the frequency of existing alleles. Students are encouraged to discuss new information to consider key points and understanding checks in a range of forms are used to enable them to check their progress and address any misconceptions. Students are provided with three articles on Huntington’s disease in South Africa, the Caribbean lizards and the plains bison to understand how either a sharp reduction in numbers of a new population beginning from a handful of individuals results in a small gene pool. Links to related topics are made throughout the lesson to ensure that a deep understanding is gained.

This fully-resourced lesson explores how new species arise when changes in the gene pool of two populations prevents members from interbreeding and producing fertile offspring. The engaging PowerPoint and accompanying resources have been designed to cover the fifth part of point 7.3 of the AQA A-level Biology specification which states that students should be able to describe allopatric and sympatric speciation. The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This fully-resourced lesson looks at the coordination and control of heart rate by the cardiovascular centre in the medulla oblongata. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the second part of point 6.1.3 of the AQA A-level Biology specification which states that students should know the roles and locations of the sensory receptors and the roles of the autonomic nervous system and effectors in the control of heart rate. This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work This lesson has been written to tie in with the previous lesson on the conducting system of the heart which is also detailed in specification point 6.1.3

This fully-resourced lesson describes how DNA is replicated semi-conservatively, including the roles of DNA helicase, polymerase and ligase. The detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (ii) of the Edexcel A-level Biology B specification The main focus of this lesson is the roles of DNA helicase in the breaking of the hydrogen bonds between nucleotide bases, DNA polymerase in forming the growing nucleotide strands and DNA ligase in the joining of the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.

This detailed lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer, cholesterol and membrane proteins. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 2.2 (i) of the Edexcel International A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model which is covered in the following lesson Students met triglycerides in topic 1 and so a quick quiz competition at the start of the lesson challenges their recall of the structure of these lipids so that they can recognise the similarities and differences to the structure of phospholipids. Time is taken to look at the differing properties of the phosphate head and the fatty acid tails in terms of water and the class is challenged to work out how the phospholipids must be arranged when there’s an aqueous solution on the inside and outside of the cell. This introduces the bilayer arrangement, with the hydrophilic phosphate heads protruding outwards into the aqueous solutions on the inside and the outside of the cell. In a link to some upcoming lessons on the transport mechanisms, the students will learn that only small, non-polar molecules can move by simple diffusion and that this is through the tails of the bilayer. This introduces the need for transmembrane proteins to allow large or polar molecules to move into the cell by facilitated diffusion and active transport. Proteins that act as receptors as also introduced and an opportunity is taken to make a link to an upcoming topic so that students can understand how hormones or drugs will bind to target cells in this way. Moving forwards, the structure of cholesterol is covered and students will learn that this hydrophobic molecule sits in the middle of the tails and therefore acts to regulate membrane fluidity. The final part of the lesson challenges the students to apply their newly-acquired knowledge to a series of questions where they have to explain why proteins may have moved when two cells are fused and to suggest why there is a larger proportion of these proteins in the inner mitochondrial membrane than the outer membrane.

This lesson describes how the role of carrier of proteins and ATP in active transport and the co-transport of sodium ions and glucose in the ileum. The PowerPoint and accompanying resources are part of the final lesson in a series of 3 that have been designed to cover the details of point 2.3 of the AQA A-level Biology specification and also includes descriptions of endocytosis and exocytosis The start of the lesson focuses on the structure of this energy currency and challenges the students prior knowledge as they covered ATP in topic 1.6. As a result, they will recall that this molecule consists of adenine, ribose and three phosphate groups and that in order to release the stored energy, ATP must be hydrolysed. Time is taken to emphasise the key point that the hydrolysis of ATP can be coupled to energy-requiring reactions and this leads into a series of exam-style questions where students are challenged on their knowledge of simple and facilitated diffusion to recognise that ATP is needed for active transport. These questions also challenge them to compare active transport against the forms of passive transport and to use data from a bar chart to support this form of transport. In answering these questions they will discover that carrier proteins are specific to certain molecules and time is taken to look at the exact mechanism of these transmembrane proteins. A quick quiz round introduces endocytosis and the students will see how vesicles are involved along with the energy source of ATP to move large substances in or out of the cell. The students are then shown how exocytosis is involved in a synapse and in the release of ADH from the pituitary gland during osmoregulation which they will cover in later topics. The final part of the lesson describes the movement of sodium ions and glucose from the ileum to the epithelial cells to the blood using a range of proteins which includes cotransporter proteins and students will learn that similar mechanisms are seen in the phloem and in the proximal convoluted tubule.

This fully-resourced lesson describes how Mycobacterium tuberculosis and human immunodeficiency virus infect human cells and cause symptoms. The PowerPoint and accompanying resources have been designed to cover point 6.6 in unit 4 of the Edexcel International A-level Biology specification and ties in closely with the previous lesson where the structure of bacteria and viruses were compared. The lesson begins by ensuring that students recognise that TB is caused by the infection of a species of bacteria known as Mycobacterium tuberculosis and they will challenged to use their knowledge of scientific classification to recall that this pathogen is found in the mycobacteria genus. At this point, the students are told that the cell walls of this genus contain mycolic acids and later in the lesson they will have to work out that this specialist feature enables this pathogen to survive phagocytosis. A series of exam-style questions will challenge their knowledge of the respiratory and immune systems as they can understand how the bacterium travels to the alveoli where it is engulfed by a macrophage. Key terms like granuloma and necrosis are introduced and the sequence of events that occur following the formation of this aggregate of cells is described. The structure of viruses was covered during the previous lesson, so this next part of the lesson starts by challenging the students to recall the capsid, genetic material in the form of viral RNA and the lipid envelope. At this point, the students are introduced to gp120, the glycoprotein which is exposed on the surface of the lipid envelope, as this structure is critical for the entry of the virus into host cells. Students will annotate a basic diagram of HIV with these four structures which also has gp41 labelled. A quick quiz competition introduces the names of the enzymes found inside the capsid Moving forwards, the main task of this part of the lesson describes how HIV binds to the helper T cells, injects its capsid and integrates its DNA into the host’s genome in order to replicate to form virus particles (virions). Students are guided through the formation of a detailed answer about the mechanism of HIV and have to input key terms and structures where information is missing. Students will learn that the increase in the number of virus particles and a decrease in helper T cells and other immune cells results in infections like TB and by opportunistic pathogens and that this stage is recognised as AIDS

This fully-resourced lesson describes the differences between the roles of the B cells and T cells in the body’s immune response. The PowerPoint and accompanying resources have been designed to cover points 6.9 & 6.10 in unit 4 of the Edexcel International A-level Biology specification and includes descriptions of the role of the antigens and the production of antibodies by plasma (effector) cells In the previous lesson on the non-specific responses, the students were introduced to macrophages and dendritic cells as antigen-presenting cells and the start of this lesson challenges their recall and understanding of this process. Time is taken to discuss how the contact between these cells and lymphocytes is critical for the initiation of the body’s (specific) immune response. Moving forwards, a quick quiz competition is used to introduce the names of the different T cells that result from differentiation. Their specific roles are described including an emphasis on the importance of the release of cytokines in cell signalling to activate other immune system cells. T memory cells are also introduced so that students can understand their role in immunological memory and active immunity as described in an upcoming lesson. The next part of the lesson focuses on the B cells and describes how clonal selection and clonal expansion results in the formation of memory B cells and effector cells. A series of understanding and application questions are then used to introduce the structure of antibodies and to explain how the complementary shape of the variable region allows the antigen-antibody complex to be formed. The lesson concludes by emphasising that the pathogen will be overcome as a result of the combination of the actions of phagocytes, T killer cells and the antibodies released by the effector cells

This fully-resourced lesson describes how Mycobacterium tuberculosis and Human Immunodeficiency virus infect human cells. The PowerPoint and accompanying resources have been designed to cover point 6.6 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and ties in directly with the previous lesson where the structure of bacteria and viruses were compared. The lesson begins by ensuring that students recognise that TB is caused by the infection of a species of bacteria known as Mycobacterium tuberculosis and they will challenged to use their knowledge of scientific classification to recall that this pathogen is found in the mycobacteria genus. At this point, the students are told that the cell walls of this genus contain mycolic acids and later in the lesson they will have to work out that this specialist feature enables this pathogen to survive phagocytosis. A series of exam-style questions will challenge their knowledge of the respiratory and immune systems as they can understand how the bacterium travels to the alveoli where it is engulfed by a macrophage. Key terms like granuloma and necrosis are introduced and the sequence of events that occur following the formation of this aggregate of cells is described. The structure of viruses was covered during the previous lesson, so this next part of the lesson starts by challenging the students to recall the capsid, genetic material in the form of viral RNA and the lipid envelope. At this point, the students are introduced to gp120, the glycoprotein which is exposed on the surface of the lipid envelope, as this structure is critical for the entry of the virus into host cells. Students will annotate a basic diagram of HIV with these four structures which also has gp41 labelled. A quick quiz competition introduces the names of the enzymes found inside the capsid Moving forwards, the main task of this part of the lesson describes how HIV binds to the helper T cells, injects its capsid and integrates its DNA into the host’s genome in order to replicate to form virus particles (virions). Students are guided through the formation of a detailed answer about the mechanism of HIV and have to input key terms and structures where information is missing. Students will learn that the increase in the number of virus particles and a decrease in helper T cells and other immune cells results in infections like TB and by opportunistic pathogens and that this stage is recognised as AIDS

This lesson describes and explains how production is affected by a range of farming practices designed to increase the efficiency of energy transfer. The PowerPoint and accompanying resources are part of the third lesson in a series of 3 which have been designed to cover the detail included in specification point 5.3 of the AQA A-level Biology specification. Over the course of the lesson, a range of tasks which include exam-style questions with displayed mark schemes, guided discussion periods and quick quiz competitions will introduce and consider the following farming practices: raising herbivores to reduce the number of trophic levels in a food chain intensely rearing animals to reduce respiratory losses in human food chains the use of fungicides, insecticides and herbicides the addition of artificial fertilisers The ethical issues raised by these practices are also considered and alternative methods discussed such as the addition of natural predators and the use of organic fertilisers like manure As this is the last lesson in topic 5.3, it has been specifically planned to challenge the students on their knowledge of the previous two lessons and this includes a series of questions linking farming practice to the formula to calculate net production

This fully-resourced lesson describes the meaning of the terms stem cell, pluripotency and totipotency. The PowerPoint and accompanying worksheets have been designed to cover points 3.11 (i) and (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and therefore this lesson also contains discussion periods where the topic is the decisions that the scientific community have to make about the use of stem cells in medical therapies. The lesson begins with a knowledge recall of the structure of eukaryotic cells and the students have to use the first letters of each of the four answers to reveal the key term, stem cell. Time is then taken to consider the meaning of cellular differentiation, and this leads into the key idea that not all stem cells are equal when it comes to the number of cell types that they have the potential to differentiate into. A quick quiz round introduces the five degrees of potency, and then the students are challenged to use their understanding of terminology to place totipotency, pluripotency, multipotency, oligopotency and unipotency in the correct places on the potency continuum. Although the latter three do not have to be specifically known based on the content of specification point 3.11 (i), an understanding of their meaning was deemed helpful when planning the lesson as it should assist with the retention of knowledge about totipotency and pluripotency. These two highest degrees of potency are the main focus of the lesson, and key details are emphasised such as the ability of totipotent cells to differentiate into any extra-embroyonic cell, which the pluripotent cells are unable to do. The morula, and inner cell mass and trophoblast of the blastocyst are used to demonstrate these differences in potency. The final part of the lesson discusses the decisions that the scientific community have to make about the use of embryonic stem cells, adult stem cells and also foetal stem cells which allows for a link to chorionic villus sampling from topic 2. There is also a Maths in a Biology context question included in the lesson (when introducing the morula) to ensure that students continue to be prepared for the numerous calculations that they will have to tackle in the terminal exams. This resource has been differentiated two ways to allow students of differing abilities to access the work